Patients harboring uncommon EGFR exon 19 deletion-insertion mutations respond well to first-generation EGFR inhibitors and osimeritinib upon acquisition of T790M

Table 1 Baseline characteristics of the NSCLC patients with EGFR 19delins or EGFR 19del

	Characteristics	19delins (n = 41)	19del (n = 41)	P value
Age, years	Median (range)	60 (30–75)	60 (34–76)	0.638
Sex	Male	17	11	0.162
Sex	Female	24	30
Smoking status	Never	34	34	1.000
Smoking status	Smoker	7	7
Histological type	Adenocarcinoma	40	41	1.000
Histological type	Squamous carcinoma	1	0
TNM stage	IIIB	0	0	1.000
TNM stage	IV	41	41
ECOG PFS score	0 or 1	34	31	0.414
ECOG PFS score	2	7	10
Brain metastases	No	25	27	0.647
Brain metastases	Yes	16	14
EGFR 19delins variants	p.L747_P753delinsS	10
	p.L747_A750delinsP	9
	p.L747_T751delinsP	6
	p.E746_S752delinsV	3
	Other EGFR 19delins	13
EGFR 19del variants	p.E746_A750del		36
	p.L747_S752del		3
	P.L747_T751del		2
First-line treatment	Gefitinib	24	25	0.973
	Icotinib	15	14
	Erlotinib	2	2

19delins, EGFR exon 19 deletion-insertion; 19del, EGFR exon 19 deletion; ECOG PS Eastern Cooperative Oncology Group performance status